X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/502d9230ec570254fed51ae721c1da50944a5cbf..b1fc363696b1a308e6bce75eb292bacc8f2c9833:/pp.c

diff --git a/pp.c b/pp.c
index 3551d8f..9cedc3f 100644
--- a/pp.c
+++ b/pp.c
@@ -1,7 +1,7 @@
 /*    pp.c
  *
- *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
- *    2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 by Larry Wall and others
+ *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
+ *    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
  *
  *    You may distribute under the terms of either the GNU General Public
  *    License or the Artistic License, as specified in the README file.
@@ -9,8 +9,11 @@
  */
 
 /*
- * "It's a big house this, and very peculiar.  Always a bit more to discover,
- * and no knowing what you'll find around a corner.  And Elves, sir!" --Samwise
+ * 'It's a big house this, and very peculiar.  Always a bit more
+ *  to discover, and no knowing what you'll find round a corner.
+ *  And Elves, sir!'                            --Samwise Gamgee
+ *
+ *     [p.225 of _The Lord of the Rings_, II/i: "Many Meetings"]
  */
 
 /* This file contains general pp ("push/pop") functions that execute the
@@ -75,23 +78,23 @@ PP(pp_padav)
     }
     gimme = GIMME_V;
     if (gimme == G_ARRAY) {
-	const I32 maxarg = AvFILL((AV*)TARG) + 1;
+	const I32 maxarg = AvFILL(MUTABLE_AV(TARG)) + 1;
 	EXTEND(SP, maxarg);
 	if (SvMAGICAL(TARG)) {
 	    U32 i;
 	    for (i=0; i < (U32)maxarg; i++) {
-		SV * const * const svp = av_fetch((AV*)TARG, i, FALSE);
+		SV * const * const svp = av_fetch(MUTABLE_AV(TARG), i, FALSE);
 		SP[i+1] = (svp) ? *svp : &PL_sv_undef;
 	    }
 	}
 	else {
-	    Copy(AvARRAY((AV*)TARG), SP+1, maxarg, SV*);
+	    Copy(AvARRAY((const AV *)TARG), SP+1, maxarg, SV*);
 	}
 	SP += maxarg;
     }
     else if (gimme == G_SCALAR) {
 	SV* const sv = sv_newmortal();
-	const I32 maxarg = AvFILL((AV*)TARG) + 1;
+	const I32 maxarg = AvFILL(MUTABLE_AV(TARG)) + 1;
 	sv_setiv(sv, maxarg);
 	PUSHs(sv);
     }
@@ -119,7 +122,7 @@ PP(pp_padhv)
 	RETURNOP(do_kv());
     }
     else if (gimme == G_SCALAR) {
-	SV* const sv = Perl_hv_scalar(aTHX_ (HV*)TARG);
+	SV* const sv = Perl_hv_scalar(aTHX_ MUTABLE_HV(TARG));
 	SETs(sv);
     }
     RETURN;
@@ -137,17 +140,17 @@ PP(pp_rv2gv)
 
 	sv = SvRV(sv);
 	if (SvTYPE(sv) == SVt_PVIO) {
-	    GV * const gv = (GV*) sv_newmortal();
+	    GV * const gv = MUTABLE_GV(sv_newmortal());
 	    gv_init(gv, 0, "", 0, 0);
-	    GvIOp(gv) = (IO *)sv;
+	    GvIOp(gv) = MUTABLE_IO(sv);
 	    SvREFCNT_inc_void_NN(sv);
-	    sv = (SV*) gv;
+	    sv = MUTABLE_SV(gv);
 	}
-	else if (SvTYPE(sv) != SVt_PVGV)
+	else if (!isGV_with_GP(sv))
 	    DIE(aTHX_ "Not a GLOB reference");
     }
     else {
-	if (SvTYPE(sv) != SVt_PVGV) {
+	if (!isGV_with_GP(sv)) {
 	    if (SvGMAGICAL(sv)) {
 		mg_get(sv);
 		if (SvROK(sv))
@@ -158,14 +161,14 @@ PP(pp_rv2gv)
 		 * NI-S 1999/05/07
 		 */
 		if (SvREADONLY(sv))
-		    Perl_croak(aTHX_ PL_no_modify);
+		    Perl_croak(aTHX_ "%s", PL_no_modify);
 		if (PL_op->op_private & OPpDEREF) {
 		    GV *gv;
 		    if (cUNOP->op_targ) {
 			STRLEN len;
 			SV * const namesv = PAD_SV(cUNOP->op_targ);
 			const char * const name = SvPV(namesv, len);
-			gv = (GV*)newSV(0);
+			gv = MUTABLE_GV(newSV(0));
 			gv_init(gv, CopSTASH(PL_curcop), name, len, 0);
 		    }
 		    else {
@@ -173,7 +176,7 @@ PP(pp_rv2gv)
 			gv = newGVgen(name);
 		    }
 		    prepare_SV_for_RV(sv);
-		    SvRV_set(sv, (SV*)gv);
+		    SvRV_set(sv, MUTABLE_SV(gv));
 		    SvROK_on(sv);
 		    SvSETMAGIC(sv);
 		    goto wasref;
@@ -188,10 +191,11 @@ PP(pp_rv2gv)
 	    if ((PL_op->op_flags & OPf_SPECIAL) &&
 		!(PL_op->op_flags & OPf_MOD))
 	    {
-		SV * const temp = (SV*)gv_fetchsv(sv, 0, SVt_PVGV);
+		SV * const temp = MUTABLE_SV(gv_fetchsv(sv, 0, SVt_PVGV));
 		if (!temp
 		    && (!is_gv_magical_sv(sv,0)
-			|| !(sv = (SV*)gv_fetchsv(sv, GV_ADD, SVt_PVGV)))) {
+			|| !(sv = MUTABLE_SV(gv_fetchsv(sv, GV_ADD,
+							SVt_PVGV))))) {
 		    RETSETUNDEF;
 		}
 		sv = temp;
@@ -206,12 +210,12 @@ PP(pp_rv2gv)
 		       things.  */
 		    RETURN;
 		}
-		sv = (SV*)gv_fetchsv(sv, GV_ADD, SVt_PVGV);
+		sv = MUTABLE_SV(gv_fetchsv(sv, GV_ADD, SVt_PVGV));
 	    }
 	}
     }
     if (PL_op->op_private & OPpLVAL_INTRO)
-	save_gp((GV*)sv, !(PL_op->op_flags & OPf_SPECIAL));
+	save_gp(MUTABLE_GV(sv), !(PL_op->op_flags & OPf_SPECIAL));
     SETs(sv);
     RETURN;
 }
@@ -283,9 +287,9 @@ PP(pp_rv2sv)
 	}
     }
     else {
-	gv = (GV*)sv;
+	gv = MUTABLE_GV(sv);
 
-	if (SvTYPE(gv) != SVt_PVGV) {
+	if (!isGV_with_GP(gv)) {
 	    if (SvGMAGICAL(sv)) {
 		mg_get(sv);
 		if (SvROK(sv))
@@ -300,11 +304,11 @@ PP(pp_rv2sv)
     if (PL_op->op_flags & OPf_MOD) {
 	if (PL_op->op_private & OPpLVAL_INTRO) {
 	    if (cUNOP->op_first->op_type == OP_NULL)
-		sv = save_scalar((GV*)TOPs);
+		sv = save_scalar(MUTABLE_GV(TOPs));
 	    else if (gv)
 		sv = save_scalar(gv);
 	    else
-		Perl_croak(aTHX_ PL_no_localize_ref);
+		Perl_croak(aTHX_ "%s", PL_no_localize_ref);
 	}
 	else if (PL_op->op_private & OPpDEREF)
 	    vivify_ref(sv, PL_op->op_private & OPpDEREF);
@@ -316,11 +320,11 @@ PP(pp_rv2sv)
 PP(pp_av2arylen)
 {
     dVAR; dSP;
-    AV * const av = (AV*)TOPs;
-    SV ** const sv = Perl_av_arylen_p(aTHX_ (AV*)av);
+    AV * const av = MUTABLE_AV(TOPs);
+    SV ** const sv = Perl_av_arylen_p(aTHX_ MUTABLE_AV(av));
     if (!*sv) {
 	*sv = newSV_type(SVt_PVMG);
-	sv_magic(*sv, (SV*)av, PERL_MAGIC_arylen, NULL, 0);
+	sv_magic(*sv, MUTABLE_SV(av), PERL_MAGIC_arylen, NULL, 0);
     }
     SETs(*sv);
     RETURN;
@@ -376,7 +380,7 @@ PP(pp_rv2cv)
     CV *cv = sv_2cv(TOPs, &stash_unused, &gv, flags);
     if (cv) {
 	if (CvCLONE(cv))
-	    cv = (CV*)sv_2mortal((SV*)cv_clone(cv));
+	    cv = MUTABLE_CV(sv_2mortal(MUTABLE_SV(cv_clone(cv))));
 	if ((PL_op->op_private & OPpLVAL_INTRO)) {
 	    if (gv && GvCV(gv) == cv && (gv = gv_autoload4(GvSTASH(gv), GvNAME(gv), GvNAMELEN(gv), FALSE)))
 		cv = GvCV(gv);
@@ -385,11 +389,11 @@ PP(pp_rv2cv)
 	}
     }
     else if ((flags == (GV_ADD|GV_NOEXPAND)) && gv && SvROK(gv)) {
-	cv = (CV*)gv;
+	cv = MUTABLE_CV(gv);
     }    
     else
-	cv = (CV*)&PL_sv_undef;
-    SETs((SV*)cv);
+	cv = MUTABLE_CV(&PL_sv_undef);
+    SETs(MUTABLE_SV(cv));
     RETURN;
 }
 
@@ -472,11 +476,11 @@ PP(pp_prototype)
 PP(pp_anoncode)
 {
     dVAR; dSP;
-    CV* cv = (CV*)PAD_SV(PL_op->op_targ);
+    CV *cv = MUTABLE_CV(PAD_SV(PL_op->op_targ));
     if (CvCLONE(cv))
-	cv = (CV*)sv_2mortal((SV*)cv_clone(cv));
+	cv = MUTABLE_CV(sv_2mortal(MUTABLE_SV(cv_clone(cv))));
     EXTEND(SP,1);
-    PUSHs((SV*)cv);
+    PUSHs(MUTABLE_SV(cv));
     RETURN;
 }
 
@@ -522,8 +526,8 @@ S_refto(pTHX_ SV *sv)
 	    SvREFCNT_inc_void_NN(sv);
     }
     else if (SvTYPE(sv) == SVt_PVAV) {
-	if (!AvREAL((AV*)sv) && AvREIFY((AV*)sv))
-	    av_reify((AV*)sv);
+	if (!AvREAL((const AV *)sv) && AvREIFY((const AV *)sv))
+	    av_reify(MUTABLE_AV(sv));
 	SvTEMP_off(sv);
 	SvREFCNT_inc_void_NN(sv);
     }
@@ -588,7 +592,7 @@ PP(pp_gelem)
 
     SV *sv = POPs;
     const char * const elem = SvPV_nolen_const(sv);
-    GV * const gv = (GV*)POPs;
+    GV * const gv = MUTABLE_GV(POPs);
     SV * tmpRef = NULL;
 
     sv = NULL;
@@ -598,33 +602,33 @@ PP(pp_gelem)
 	switch (*elem) {
 	case 'A':
 	    if (strEQ(second_letter, "RRAY"))
-		tmpRef = (SV*)GvAV(gv);
+		tmpRef = MUTABLE_SV(GvAV(gv));
 	    break;
 	case 'C':
 	    if (strEQ(second_letter, "ODE"))
-		tmpRef = (SV*)GvCVu(gv);
+		tmpRef = MUTABLE_SV(GvCVu(gv));
 	    break;
 	case 'F':
 	    if (strEQ(second_letter, "ILEHANDLE")) {
 		/* finally deprecated in 5.8.0 */
 		deprecate("*glob{FILEHANDLE}");
-		tmpRef = (SV*)GvIOp(gv);
+		tmpRef = MUTABLE_SV(GvIOp(gv));
 	    }
 	    else
 		if (strEQ(second_letter, "ORMAT"))
-		    tmpRef = (SV*)GvFORM(gv);
+		    tmpRef = MUTABLE_SV(GvFORM(gv));
 	    break;
 	case 'G':
 	    if (strEQ(second_letter, "LOB"))
-		tmpRef = (SV*)gv;
+		tmpRef = MUTABLE_SV(gv);
 	    break;
 	case 'H':
 	    if (strEQ(second_letter, "ASH"))
-		tmpRef = (SV*)GvHV(gv);
+		tmpRef = MUTABLE_SV(GvHV(gv));
 	    break;
 	case 'I':
 	    if (*second_letter == 'O' && !elem[2])
-		tmpRef = (SV*)GvIOp(gv);
+		tmpRef = MUTABLE_SV(GvIOp(gv));
 	    break;
 	case 'N':
 	    if (strEQ(second_letter, "AME"))
@@ -803,47 +807,52 @@ PP(pp_undef)
     case SVt_NULL:
 	break;
     case SVt_PVAV:
-	av_undef((AV*)sv);
+	av_undef(MUTABLE_AV(sv));
 	break;
     case SVt_PVHV:
-	hv_undef((HV*)sv);
+	hv_undef(MUTABLE_HV(sv));
 	break;
     case SVt_PVCV:
-	if (cv_const_sv((CV*)sv) && ckWARN(WARN_MISC))
+	if (cv_const_sv((const CV *)sv) && ckWARN(WARN_MISC))
 	    Perl_warner(aTHX_ packWARN(WARN_MISC), "Constant subroutine %s undefined",
-		 CvANON((CV*)sv) ? "(anonymous)" : GvENAME(CvGV((CV*)sv)));
+		 CvANON((const CV *)sv) ? "(anonymous)"
+			: GvENAME(CvGV((const CV *)sv)));
 	/* FALLTHROUGH */
     case SVt_PVFM:
 	{
 	    /* let user-undef'd sub keep its identity */
-	    GV* const gv = CvGV((CV*)sv);
-	    cv_undef((CV*)sv);
-	    CvGV((CV*)sv) = gv;
+	    GV* const gv = CvGV((const CV *)sv);
+	    cv_undef(MUTABLE_CV(sv));
+	    CvGV((const CV *)sv) = gv;
 	}
 	break;
     case SVt_PVGV:
-	if (SvFAKE(sv))
+	if (SvFAKE(sv)) {
 	    SvSetMagicSV(sv, &PL_sv_undef);
-	else {
+	    break;
+	}
+	else if (isGV_with_GP(sv)) {
 	    GP *gp;
             HV *stash;
 
             /* undef *Foo:: */
-            if((stash = GvHV((GV*)sv)) && HvNAME_get(stash))
+            if((stash = GvHV((const GV *)sv)) && HvNAME_get(stash))
                 mro_isa_changed_in(stash);
             /* undef *Pkg::meth_name ... */
-            else if(GvCVu((GV*)sv) && (stash = GvSTASH((GV*)sv)) && HvNAME_get(stash))
+            else if(GvCVu((const GV *)sv) && (stash = GvSTASH((const GV *)sv))
+		    && HvNAME_get(stash))
                 mro_method_changed_in(stash);
 
-	    gp_free((GV*)sv);
+	    gp_free(MUTABLE_GV(sv));
 	    Newxz(gp, 1, GP);
 	    GvGP(sv) = gp_ref(gp);
 	    GvSV(sv) = newSV(0);
 	    GvLINE(sv) = CopLINE(PL_curcop);
-	    GvEGV(sv) = (GV*)sv;
+	    GvEGV(sv) = MUTABLE_GV(sv);
 	    GvMULTI_on(sv);
+	    break;
 	}
-	break;
+	/* FALL THROUGH */
     default:
 	if (SvTYPE(sv) >= SVt_PV && SvPVX_const(sv) && SvLEN(sv)) {
 	    SvPV_free(sv);
@@ -860,8 +869,8 @@ PP(pp_undef)
 PP(pp_predec)
 {
     dVAR; dSP;
-    if (SvTYPE(TOPs) >= SVt_PVGV && SvTYPE(TOPs) != SVt_PVLV)
-	DIE(aTHX_ PL_no_modify);
+    if (SvTYPE(TOPs) >= SVt_PVAV || isGV_with_GP(TOPs))
+	DIE(aTHX_ "%s", PL_no_modify);
     if (!SvREADONLY(TOPs) && SvIOK_notUV(TOPs) && !SvNOK(TOPs) && !SvPOK(TOPs)
         && SvIVX(TOPs) != IV_MIN)
     {
@@ -877,8 +886,8 @@ PP(pp_predec)
 PP(pp_postinc)
 {
     dVAR; dSP; dTARGET;
-    if (SvTYPE(TOPs) >= SVt_PVGV && SvTYPE(TOPs) != SVt_PVLV)
-	DIE(aTHX_ PL_no_modify);
+    if (SvTYPE(TOPs) >= SVt_PVAV || isGV_with_GP(TOPs))
+	DIE(aTHX_ "%s", PL_no_modify);
     sv_setsv(TARG, TOPs);
     if (!SvREADONLY(TOPs) && SvIOK_notUV(TOPs) && !SvNOK(TOPs) && !SvPOK(TOPs)
         && SvIVX(TOPs) != IV_MAX)
@@ -899,8 +908,8 @@ PP(pp_postinc)
 PP(pp_postdec)
 {
     dVAR; dSP; dTARGET;
-    if (SvTYPE(TOPs) >= SVt_PVGV && SvTYPE(TOPs) != SVt_PVLV)
-	DIE(aTHX_ PL_no_modify);
+    if (SvTYPE(TOPs) >= SVt_PVAV || isGV_with_GP(TOPs))
+	DIE(aTHX_ "%s", PL_no_modify);
     sv_setsv(TARG, TOPs);
     if (!SvREADONLY(TOPs) && SvIOK_notUV(TOPs) && !SvNOK(TOPs) && !SvPOK(TOPs)
         && SvIVX(TOPs) != IV_MIN)
@@ -1545,7 +1554,7 @@ PP(pp_repeat)
 	    }
 	    MARK++;
 	    repeatcpy((char*)(MARK + items), (char*)MARK,
-		items * sizeof(SV*), count - 1);
+		items * sizeof(const SV *), count - 1);
 	    SP += max;
 	}
 	else if (count <= 0)
@@ -2427,7 +2436,7 @@ PP(pp_negate)
 	    STRLEN len;
 	    const char * const s = SvPV_const(sv, len);
 	    if (isIDFIRST(*s)) {
-		sv_setpvn(TARG, "-", 1);
+		sv_setpvs(TARG, "-");
 		sv_catsv(TARG, sv);
 	    }
 	    else if (*s == '+' || *s == '-') {
@@ -2441,7 +2450,7 @@ PP(pp_negate)
 		if (SvNOK(sv))
 		    sv_setnv(TARG, -SvNV(sv));
 		else {
-		    sv_setpvn(TARG, "-", 1);
+		    sv_setpvs(TARG, "-");
 		    sv_catsv(TARG, sv);
 		}
 	    }
@@ -2544,7 +2553,7 @@ PP(pp_complement)
 	      sv_usepvn_flags(TARG, (char*)result, nchar, SV_HAS_TRAILING_NUL);
 	      SvUTF8_off(TARG);
 	  }
-	  SETs(TARG);
+	  SETTARG;
 	  RETURN;
 	}
 #ifdef LIBERAL
@@ -2560,8 +2569,7 @@ PP(pp_complement)
 #endif
 	for ( ; anum > 0; anum--, tmps++)
 	    *tmps = ~*tmps;
-
-	SETs(TARG);
+	SETTARG;
       }
       RETURN;
     }
@@ -3180,7 +3188,7 @@ PP(pp_substr)
 	    }
 	    if (!SvOK(sv))
 		sv_setpvs(sv, "");
-	    sv_insert(sv, pos, rem, repl, repl_len);
+	    sv_insert_flags(sv, pos, rem, repl, repl_len, 0);
 	    if (repl_is_utf8)
 		SvUTF8_on(sv);
 	    if (repl_sv_copy)
@@ -3199,7 +3207,7 @@ PP(pp_substr)
 		else if (SvOK(sv))	/* is it defined ? */
 		    (void)SvPOK_only_UTF8(sv);
 		else
-		    sv_setpvn(sv,"",0);	/* avoid lexical reincarnation */
+		    sv_setpvs(sv, ""); /* avoid lexical reincarnation */
 	    }
 
 	    if (SvTYPE(TARG) < SVt_PVLV) {
@@ -3505,7 +3513,7 @@ PP(pp_crypt)
 #   else
     sv_setpv(TARG, PerlProc_crypt(tmps, SvPV_nolen_const(right)));
 #   endif
-    SETs(TARG);
+    SETTARG;
     RETURN;
 #else
     DIE(aTHX_
@@ -3890,9 +3898,7 @@ PP(pp_quotemeta)
     }
     else
 	sv_setpvn(TARG, s, len);
-    SETs(TARG);
-    if (SvSMAGICAL(TARG))
-	mg_set(TARG);
+    SETTARG;
     RETURN;
 }
 
@@ -3901,12 +3907,22 @@ PP(pp_quotemeta)
 PP(pp_aslice)
 {
     dVAR; dSP; dMARK; dORIGMARK;
-    register AV* const av = (AV*)POPs;
+    register AV *const av = MUTABLE_AV(POPs);
     register const I32 lval = (PL_op->op_flags & OPf_MOD || LVRET);
 
     if (SvTYPE(av) == SVt_PVAV) {
 	const I32 arybase = CopARYBASE_get(PL_curcop);
-	if (lval && PL_op->op_private & OPpLVAL_INTRO) {
+	const bool localizing = PL_op->op_private & OPpLVAL_INTRO;
+	bool can_preserve = FALSE;
+
+	if (localizing) {
+	    MAGIC *mg;
+	    HV *stash;
+
+	    can_preserve = SvCANEXISTDELETE(av);
+	}
+
+	if (lval && localizing) {
 	    register SV **svp;
 	    I32 max = -1;
 	    for (svp = MARK + 1; svp <= SP; svp++) {
@@ -3917,18 +3933,32 @@ PP(pp_aslice)
 	    if (max > AvMAX(av))
 		av_extend(av, max);
 	}
+
 	while (++MARK <= SP) {
 	    register SV **svp;
 	    I32 elem = SvIV(*MARK);
+	    bool preeminent = TRUE;
 
 	    if (elem > 0)
 		elem -= arybase;
+	    if (localizing && can_preserve) {
+		/* If we can determine whether the element exist,
+		 * Try to preserve the existenceness of a tied array
+		 * element by using EXISTS and DELETE if possible.
+		 * Fallback to FETCH and STORE otherwise. */
+		preeminent = av_exists(av, elem);
+	    }
+
 	    svp = av_fetch(av, elem, lval);
 	    if (lval) {
 		if (!svp || *svp == &PL_sv_undef)
 		    DIE(aTHX_ PL_no_aelem, elem);
-		if (PL_op->op_private & OPpLVAL_INTRO)
-		    save_aelem(av, elem, svp);
+		if (localizing) {
+		    if (preeminent)
+			save_aelem(av, elem, svp);
+		    else
+			SAVEADELETE(av, elem);
+		}
 	    }
 	    *MARK = svp ? *svp : &PL_sv_undef;
 	}
@@ -3945,7 +3975,7 @@ PP(pp_aeach)
 {
     dVAR;
     dSP;
-    AV *array = (AV*)POPs;
+    AV *array = MUTABLE_AV(POPs);
     const I32 gimme = GIMME_V;
     IV *iterp = Perl_av_iter_p(aTHX_ array);
     const IV current = (*iterp)++;
@@ -3971,7 +4001,7 @@ PP(pp_akeys)
 {
     dVAR;
     dSP;
-    AV *array = (AV*)POPs;
+    AV *array = MUTABLE_AV(POPs);
     const I32 gimme = GIMME_V;
 
     *Perl_av_iter_p(aTHX_ array) = 0;
@@ -4008,7 +4038,7 @@ PP(pp_each)
 {
     dVAR;
     dSP;
-    HV * hash = (HV*)POPs;
+    HV * hash = MUTABLE_HV(POPs);
     HE *entry;
     const I32 gimme = GIMME_V;
 
@@ -4045,7 +4075,7 @@ PP(pp_delete)
 
     if (PL_op->op_private & OPpSLICE) {
 	dMARK; dORIGMARK;
-	HV * const hv = (HV*)POPs;
+	HV * const hv = MUTABLE_HV(POPs);
 	const U32 hvtype = SvTYPE(hv);
 	if (hvtype == SVt_PVHV) {			/* hash element */
 	    while (++MARK <= SP) {
@@ -4056,7 +4086,7 @@ PP(pp_delete)
 	else if (hvtype == SVt_PVAV) {                  /* array element */
             if (PL_op->op_flags & OPf_SPECIAL) {
                 while (++MARK <= SP) {
-                    SV * const sv = av_delete((AV*)hv, SvIV(*MARK), discard);
+                    SV * const sv = av_delete(MUTABLE_AV(hv), SvIV(*MARK), discard);
                     *MARK = sv ? sv : &PL_sv_undef;
                 }
             }
@@ -4076,13 +4106,13 @@ PP(pp_delete)
     }
     else {
 	SV *keysv = POPs;
-	HV * const hv = (HV*)POPs;
+	HV * const hv = MUTABLE_HV(POPs);
 	SV *sv;
 	if (SvTYPE(hv) == SVt_PVHV)
 	    sv = hv_delete_ent(hv, keysv, discard, 0);
 	else if (SvTYPE(hv) == SVt_PVAV) {
 	    if (PL_op->op_flags & OPf_SPECIAL)
-		sv = av_delete((AV*)hv, SvIV(keysv), discard);
+		sv = av_delete(MUTABLE_AV(hv), SvIV(keysv), discard);
 	    else
 		DIE(aTHX_ "panic: avhv_delete no longer supported");
 	}
@@ -4114,14 +4144,14 @@ PP(pp_exists)
 	RETPUSHNO;
     }
     tmpsv = POPs;
-    hv = (HV*)POPs;
+    hv = MUTABLE_HV(POPs);
     if (SvTYPE(hv) == SVt_PVHV) {
 	if (hv_exists_ent(hv, tmpsv, 0))
 	    RETPUSHYES;
     }
     else if (SvTYPE(hv) == SVt_PVAV) {
 	if (PL_op->op_flags & OPf_SPECIAL) {		/* array element */
-	    if (av_exists((AV*)hv, SvIV(tmpsv)))
+	    if (av_exists(MUTABLE_AV(hv), SvIV(tmpsv)))
 		RETPUSHYES;
 	}
     }
@@ -4134,34 +4164,31 @@ PP(pp_exists)
 PP(pp_hslice)
 {
     dVAR; dSP; dMARK; dORIGMARK;
-    register HV * const hv = (HV*)POPs;
+    register HV * const hv = MUTABLE_HV(POPs);
     register const I32 lval = (PL_op->op_flags & OPf_MOD || LVRET);
     const bool localizing = PL_op->op_private & OPpLVAL_INTRO;
-    bool other_magic = FALSE;
+    bool can_preserve = FALSE;
 
     if (localizing) {
         MAGIC *mg;
         HV *stash;
 
-        other_magic = mg_find((SV*)hv, PERL_MAGIC_env) ||
-            ((mg = mg_find((SV*)hv, PERL_MAGIC_tied))
-             /* Try to preserve the existenceness of a tied hash
-              * element by using EXISTS and DELETE if possible.
-              * Fallback to FETCH and STORE otherwise */
-             && (stash = SvSTASH(SvRV(SvTIED_obj((SV*)hv, mg))))
-             && gv_fetchmethod_autoload(stash, "EXISTS", TRUE)
-             && gv_fetchmethod_autoload(stash, "DELETE", TRUE));
+	if (SvCANEXISTDELETE(hv) || mg_find((const SV *)hv, PERL_MAGIC_env))
+	    can_preserve = TRUE;
     }
 
     while (++MARK <= SP) {
         SV * const keysv = *MARK;
         SV **svp;
         HE *he;
-        bool preeminent = FALSE;
-
-        if (localizing) {
-            preeminent = SvRMAGICAL(hv) && !other_magic ? 1 :
-                hv_exists_ent(hv, keysv, 0);
+        bool preeminent = TRUE;
+
+        if (localizing && can_preserve) {
+	    /* If we can determine whether the element exist,
+             * try to preserve the existenceness of a tied hash
+             * element by using EXISTS and DELETE if possible.
+             * Fallback to FETCH and STORE otherwise. */
+            preeminent = hv_exists_ent(hv, keysv, 0);
         }
 
         he = hv_fetch_ent(hv, keysv, lval, 0);
@@ -4173,10 +4200,11 @@ PP(pp_hslice)
             }
             if (localizing) {
 		if (HvNAME_get(hv) && isGV(*svp))
-		    save_gp((GV*)*svp, !(PL_op->op_flags & OPf_SPECIAL));
+		    save_gp(MUTABLE_GV(*svp), !(PL_op->op_flags & OPf_SPECIAL));
 		else {
 		    if (preeminent)
-			save_helem(hv, keysv, svp);
+			save_helem_flags(hv, keysv, svp,
+					 (PL_op->op_flags & OPf_SPECIAL) ? 0 : SAVEf_SETMAGIC);
 		    else {
 			STRLEN keylen;
 			const char * const key = SvPV_const(keysv, keylen);
@@ -4269,7 +4297,7 @@ PP(pp_anonlist)
 {
     dVAR; dSP; dMARK; dORIGMARK;
     const I32 items = SP - MARK;
-    SV * const av = (SV *) av_make(items, MARK+1);
+    SV * const av = MUTABLE_SV(av_make(items, MARK+1));
     SP = ORIGMARK;		/* av_make() might realloc stack_sp */
     mXPUSHs((PL_op->op_flags & OPf_SPECIAL)
 	    ? newRV_noinc(av) : av);
@@ -4292,14 +4320,14 @@ PP(pp_anonhash)
     }
     SP = ORIGMARK;
     mXPUSHs((PL_op->op_flags & OPf_SPECIAL)
-	    ? newRV_noinc((SV*) hv) : (SV*) hv);
+	    ? newRV_noinc(MUTABLE_SV(hv)) : MUTABLE_SV(hv));
     RETURN;
 }
 
 PP(pp_splice)
 {
     dVAR; dSP; dMARK; dORIGMARK;
-    register AV *ary = (AV*)*++MARK;
+    register AV *ary = MUTABLE_AV(*++MARK);
     register SV **src;
     register SV **dst;
     register I32 i;
@@ -4308,10 +4336,10 @@ PP(pp_splice)
     I32 newlen;
     I32 after;
     I32 diff;
-    const MAGIC * const mg = SvTIED_mg((SV*)ary, PERL_MAGIC_tied);
+    const MAGIC * const mg = SvTIED_mg((const SV *)ary, PERL_MAGIC_tied);
 
     if (mg) {
-	*MARK-- = SvTIED_obj((SV*)ary, mg);
+	*MARK-- = SvTIED_obj(MUTABLE_SV(ary), mg);
 	PUSHMARK(MARK);
 	PUTBACK;
 	ENTER;
@@ -4504,11 +4532,11 @@ PP(pp_splice)
 PP(pp_push)
 {
     dVAR; dSP; dMARK; dORIGMARK; dTARGET;
-    register AV * const ary = (AV*)*++MARK;
-    const MAGIC * const mg = SvTIED_mg((SV*)ary, PERL_MAGIC_tied);
+    register AV * const ary = MUTABLE_AV(*++MARK);
+    const MAGIC * const mg = SvTIED_mg((const SV *)ary, PERL_MAGIC_tied);
 
     if (mg) {
-	*MARK-- = SvTIED_obj((SV*)ary, mg);
+	*MARK-- = SvTIED_obj(MUTABLE_SV(ary), mg);
 	PUSHMARK(MARK);
 	PUTBACK;
 	ENTER;
@@ -4516,7 +4544,9 @@ PP(pp_push)
 	LEAVE;
 	SPAGAIN;
 	SP = ORIGMARK;
-	PUSHi( AvFILL(ary) + 1 );
+	if (GIMME_V != G_VOID) {
+	    PUSHi( AvFILL(ary) + 1 );
+	}
     }
     else {
 	PL_delaymagic = DM_DELAY;
@@ -4527,7 +4557,7 @@ PP(pp_push)
 	    av_store(ary, AvFILLp(ary)+1, sv);
 	}
 	if (PL_delaymagic & DM_ARRAY)
-	    mg_set((SV*)ary);
+	    mg_set(MUTABLE_SV(ary));
 
 	PL_delaymagic = 0;
 	SP = ORIGMARK;
@@ -4540,7 +4570,7 @@ PP(pp_shift)
 {
     dVAR;
     dSP;
-    AV * const av = (AV*)POPs;
+    AV * const av = MUTABLE_AV(POPs);
     SV * const sv = PL_op->op_type == OP_SHIFT ? av_shift(av) : av_pop(av);
     EXTEND(SP, 1);
     assert (sv);
@@ -4553,11 +4583,11 @@ PP(pp_shift)
 PP(pp_unshift)
 {
     dVAR; dSP; dMARK; dORIGMARK; dTARGET;
-    register AV *ary = (AV*)*++MARK;
-    const MAGIC * const mg = SvTIED_mg((SV*)ary, PERL_MAGIC_tied);
+    register AV *ary = MUTABLE_AV(*++MARK);
+    const MAGIC * const mg = SvTIED_mg((const SV *)ary, PERL_MAGIC_tied);
 
     if (mg) {
-	*MARK-- = SvTIED_obj((SV*)ary, mg);
+	*MARK-- = SvTIED_obj(MUTABLE_SV(ary), mg);
 	PUSHMARK(MARK);
 	PUTBACK;
 	ENTER;
@@ -4574,7 +4604,9 @@ PP(pp_unshift)
 	}
     }
     SP = ORIGMARK;
-    PUSHi( AvFILL(ary) + 1 );
+    if (GIMME_V != G_VOID) {
+	PUSHi( AvFILL(ary) + 1 );
+    }
     RETURN;
 }
 
@@ -4604,13 +4636,18 @@ PP(pp_reverse)
 	SvUTF8_off(TARG);				/* decontaminate */
 	if (SP - MARK > 1)
 	    do_join(TARG, &PL_sv_no, MARK, SP);
-	else
+	else {
 	    sv_setsv(TARG, (SP > MARK)
 		    ? *SP
 		    : (padoff_du = find_rundefsvoffset(),
 			(padoff_du == NOT_IN_PAD
 			 || PAD_COMPNAME_FLAGS_isOUR(padoff_du))
 			? DEFSV : PAD_SVl(padoff_du)));
+
+	    if (! SvOK(TARG) && ckWARN(WARN_UNINITIALIZED))
+		report_uninit(TARG);
+	}
+
 	up = SvPV_force(TARG, len);
 	if (len > 1) {
 	    if (DO_UTF8(TARG)) {	/* first reverse each character */
@@ -4694,7 +4731,7 @@ PP(pp_split)
 
 #ifdef USE_ITHREADS
     if (pm->op_pmreplrootu.op_pmtargetoff) {
-	ary = GvAVn((GV*)PAD_SVl(pm->op_pmreplrootu.op_pmtargetoff));
+	ary = GvAVn(MUTABLE_GV(PAD_SVl(pm->op_pmreplrootu.op_pmtargetoff)));
     }
 #else
     if (pm->op_pmreplrootu.op_pmtargetgv) {
@@ -4711,9 +4748,9 @@ PP(pp_split)
 	av_extend(ary,0);
 	av_clear(ary);
 	SPAGAIN;
-	if ((mg = SvTIED_mg((SV*)ary, PERL_MAGIC_tied))) {
+	if ((mg = SvTIED_mg((const SV *)ary, PERL_MAGIC_tied))) {
 	    PUSHMARK(SP);
-	    XPUSHs(SvTIED_obj((SV*)ary, mg));
+	    XPUSHs(SvTIED_obj(MUTABLE_SV(ary), mg));
 	}
 	else {
 	    if (!AvREAL(ary)) {
@@ -4968,7 +5005,7 @@ PP(pp_split)
 	if (!mg) {
 	    if (SvSMAGICAL(ary)) {
 		PUTBACK;
-		mg_set((SV*)ary);
+		mg_set(MUTABLE_SV(ary));
 		SPAGAIN;
 	    }
 	    if (gimme == G_ARRAY) {
@@ -5025,9 +5062,9 @@ PP(pp_lock)
     dSP;
     dTOPss;
     SV *retsv = sv;
+    assert(SvTYPE(retsv) != SVt_PVCV);
     SvLOCK(sv);
-    if (SvTYPE(retsv) == SVt_PVAV || SvTYPE(retsv) == SVt_PVHV
-	|| SvTYPE(retsv) == SVt_PVCV) {
+    if (SvTYPE(retsv) == SVt_PVAV || SvTYPE(retsv) == SVt_PVHV) {
 	retsv = refto(retsv);
     }
     SETs(retsv);